Findings and Recommendations - New Research Opportunities in the Earth Sciences - page 99

BIOGEOCHEMICAL AND WATER CYCLES IN
TERRESTRIAL ENVIRONMENTS AND IMPACTS OF GLOBAL CHANGE
Humans are altering the physical, chemical, and biological states and
feedbacks among essential components of the Earth surface system. At the same time,
atmospheric temperature and carbon dioxide levels have increased and are impacting
carbon storage in the terrestrial environment, the water cycle, and a range of
intertwined biogeochemical cycles and atmospheric properties that feed back on
climate and ecosystems. Advancing our understanding of integrated soil, water, and
biogeochemical dynamics in the critical zone and the responses and feedbacks of
carbon, nitrogen, and water cycles to climate change and human impacts requires new
theory, coupled systems models, and new data. Several reports and science plans
underscore the need for integrated studies of biogeochemical and water cycles in
terrestrial environments, particularly in the critical zone, and their response to climate
and land use change, including Landscapes on the Edge (NRC, 2010a), Challenges
and Opportunities in the Hydrologic Sciences (NRC, in preparation), Frontiers in
Exploration of the Critical Zone (Brantley et al., 2006), A Plan for a New Science
Initiative on the Global Water Cycle (USGCRP, 2001), and the BROES report (NRC,
2001).
Among the key research opportunities is development of a theoretical
framework for the interactions among hydrological, geochemical, geomorphic, and
biological processes in the critical zone, including the roles of climate and geological
setting that have heretofore been only loosely constrained. New advances in our
ability to understand and quantitatively simulate carbon, nutrient, water, and rock
cycling will depend on new measurement approaches and instrumentation that
capture spatial and temporal variability in atmospheric and land use inputs
superimposed on complex vegetation patterns and underlying anisotropic subsurface
geomedia. This will require a substantial investment in in situ environmental sensors,
field instruments, geochemical and microbiological tools, remote sensing, surface and
subsurface imaging, and development of new technologies. There is also a critical
need for development of coupled systems models to explore how these systems
respond to anthropogenic and climatic forcing.
Finding 1: EAR is poised to play a leadership role in comprehensive, uniquely
integrated studies of the terrestrial environment in the face of human activity and
climate change. New efforts could coordinate with complementary NSF programs in
hydrology, geomorphology, sedimentology, climatology, atmospheric science,
geodesy, geophysics, geochemistry, geobiology, and terrestrial ecology, as well as the
National Ecological Observatory Network (NEON). Extending this coordination to
related programs outside NSF could be valuable.
Finding 2: The Critical Zone Observatory (CZO) model provides a fruitful template
for evaluation and possible expansion of integrated studies of the critical zone in
complex terrestrial settings. These observatories and other integrated approaches are
most valuable if they capture a broad, but differentiated, array of settings, processes,
and controls (natural and anthropogenic) and are effectively coordinated. Critically